Janet Ellis looks at how the dot has helped us communicate and reflects on the dot in computer language. Morse code, Braille and the dots that get our email delivered.

The simple dot is one of the first marks man ever made. From being a word we uttered infrequently, the advent of digital has made it one we use all the time.

The dot. We wear it, listen to it, read it and gaze on it. We send it through the air and under the waves. Each programme in this series circles a different aspect of this simple mark.

Contributors include Dr Tilly Blyth, Head of Collections Science Museum London, and Robert Saggers, Heritage Manager at the Royal Institute of Blind People.

Producer: Caroline Raphael
A Dora production for BBC Radio 4. Show less